Loosely connected to evolutionary theory - i.e, a women's lips are attractive to the opposite sex due their similarity to a Female's sexual organs (labia lips). Using social media, women adopt an exentuated pout (in 'selfies') to elicit heightened sexual attraction; unconsciously communicating 'i am ready for sexual activity and super fertile'.
Women who do not adopt thIs approach in 'selfies' exude a confidence and low need for attention from others - hence they are 'vag confident'.
1) She's look amazing on her face book site , she is so vag confident
2) I'd really like to get to know her; seems so cool and natural. Amazing vag confidence